Sinuous type muffler



Dec. 20, 1955 J. P. MARX SINUOUS TYPE MUFFLER Filed April 18, 1952 6% NA w Q% Q i wwwm a m /N gv/a P WZaW/z;

nited States Patent SINUOUS TYPE MUFFLER Joseph P. Marx, Hartford, Wis., assignor to Powell Muiiier Company, Inc., a corporation of Illinois Application April 18, 1952, Serial No. 282,950

2 Claims. (Cl. 181-57) This invention relates to improvements in exhaust silencers or mufiiers for expanding gases released from internal combustion engines, and more particularly to improvements in the sinuous type of mufflers disclosed in Patent Number 1,998,386 issued to Herbert S. Powell on April 16, 1935, and assigned to the assignee of the present application.

Primarily the object of this invention is to markedly increase the efficiency and degree of silencing of internal combustion engine exhaust gases over that heretofore obtainable in sinuous type mufiiers.

The advantages of sinuous type mufilers over some of the more usual types are well known. The flow of gases through a mudler in a relatively thin flat column and in a sinuous path is highly desirable from the standpoint of breaking up the regularity of the impulses ordinarily encountered in exhausts of this character. It is also well known that periodic expansion of the gases during their passage through the mufiier as well as reversal of the direction of flow of the exhaust stream is extremely effective in silencing the noises which accompany the explosive combustion of fuels in internal combustion engines. Furthermore, the velocity of the exhaust gases are thereby materially reduced.

An important object of this invention is concerned with the provision of a muffler having such a combination of structural features that all of the above advantageous phenomena are L parted to the stream of exhaust gases within the mufiler. An object relating thereto is to so construct the muflier that each phenomena is practiced in its most eifective manner and without one interfering with, or detracting from, the other.

A further object is to provide a muflier construction which will more effectively impart a sinuous flow of gases therethrough.

Another object is to afford a muffler within which the flow of gases is reversed at several points during their passage therethrough.

Still a further object is to provide an exhaust silencer construction in which the exhaust gases are permitted to expand on several occasions during their propulsion through the device.

Still another object is to afford a sinuous muflier construction having chambers which function as resonators thereby exerting a silencing action which aids in mufiling the exhaust noises.

Yet another object of the invention is to provide a mother through which the exhaust gases pass in a sinuous path, and wherein there are substantially closed pockets at each side of the path of travel of the gases, into and through which pockets the gases may pass by expansion for reducing the extent of the negative and positive impulses incident to the discharge of the exhaust gases from the engine.

Yet a further object of the invention is to provide a muffler of the above type wherein the walls constituting ice the sinuous path are so disposed as to form a relatively thin flat column of flowing gases.

And still another object is to afford a sinuous type mufiler of comparatively simple and inexpensive design but yet efficient, effective and durable.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel features of construction, arrangement and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportion, size and minor details of the structure may be made without departing from the spirit or sacrificing any of the advantages of the invention.

For the purpose of facilitating an understanding of my invention, I have illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, my invention, its mode of construction, assembly and operation, and many of its advantages should be readily understood and appreciated.

Referring to the drawings in which the same characters of reference are employed to indicate corresponding or similar parts throughout the several figures of the drawings:

Fig. l is a longitudinal cross-sectional view through a mufller in which are embodied the principles of my in vention;

Fig. 2 is an end view taken in Fig. 1 through the inlet section;

Fig. 3 is a transverse sectional view taken on the plane of line 3-3 in Fig. l and showing the central baffle-plate in front elevation; and

Fig. 4 is a transverse sectional view taken on the plane of line 44 in Fig. l and with certain portions of the inner wall cut away to better illustrate the construction.

Turning now to a more detailed examination of the several figures of dicates generally the illustrated embodiment of my invention comprising a muffler with an elongated, cylindrical casing 12, which may be of elliptical cross-section or circular as shown in Figs. 2, 3 and 4. The casing 12 is closed at its intake end by an end wall 14 and at its outlet end by a similar end wall 16. Both end walls 14 and 16 are circumferentially outwardly flanged as at 18 and 20 respectively, which flanges are suitably secured, as by Welding, to the inner wall of the casing 12. The flanges 14, 16 are further centrally apertured and drawn to provide outwardly extending nipples 22 and 24 respectively.

The gases enter the muffler through an inlet pipe 26 at one end and are discharged at the opposite end through the outlet pipe 28. The pipes 26, 23 are secured to the respective nipples 22, 24 by means of clamping collars 30, 32.

The sinuous paths through which the gases flow are afforded within the muflier by the arrangement of a plurality of convoluted plates arranged in complementary positions to afford such paths. Two separate sinuous paths are provided; one in the lower or inlet portion of the mufiier and the other in the upper or discharge portion.

The lower or intake sinuous path 34 is defined by a pair of plates 36 and 38 bent and convoluted to afford a plurality of straight Walls, spaced one from the other. Plate 36 is convoluted into two pair of bafile walls 40, 42 and 44, 46. The walls of each pair of bafiies are connected at their inner ends by integrally formed curved segments 48, 50, and the outer ends of baflie walls 42 and 44 are on the plane of line 2-2 pipe and showing the same in the drawings, reference numeral 10 in' 3 likewise connected but by a straight unbent portion 52 of the plate 36.

The other plate 38 of the pair is similarly bent and convoluted but is positioned in complementary staggered relationship with the first plate 36. Thus baffle walls 54, 56 and 58, 60 are provided connected at their inner ends by curved segments 62, 64 and at their outer ends by straight portion 66 of plate 38. It will be noted that the bafile walls 54, 56, 58 and 60 as well as the curved segments 62 and 64 are perforated as at 68. The function of these perforations and the reason for their confinement to the baffles of but one plate or side of the sinuous path will become apparent as the description proceeds.

Upon further examination of the sinuous path construction it will be noted that the convoluted plates 36 and 38 in addition to defining the sinuous path 34 likewise define chambers or pockets such as 70 and 72. positioned adjacent to the path. The function of these chambers will likewise be disclosed as the description proceeds.

Attention is now directed to the manner in which the plates 36 and 38 are aflixed to the inner wall of the easing 12. It will be noted that the plates are provided with end portions 74, 76 and 78, 80 which are affixed to the casing 12 as by welding. However, it will be further noted that the end portion 76 and the straight segments 52 and 66 are spaced from the wall of the casing sufficiently to afford narrow connecting passages such as 82, 84 and 86. The function of these passages will later be disclosed when the operation of the mufller is explained.

Proceeding further with the description, the upper or discharge sinuous path 88 is defined by a pair of plates 90 and 92 which have been bent and convoluted in the same manner as were the plates 36 and 38. For this reason similar parts have been designated by like numerals. However it should be noted that the construction of plate 92 is similar to that of plate 36 which is actually positioned on the other side of the muffler in the lower sinuous path structure. Likewise plate 92 is similar in construction to plate 36 which is oppositely positioned in the lower sinuous path construction. Particularly it should be noted that the perforations 68 are confined only to the baffie walls of plate 90 which is located on the side of the muffler opposite to the side on which it is positioned in the lower sinuous path construction. For the sake of clarity and uniformity the like parts of plate 90 have been designated by numerals similar to those of plate 38, and those of plate 92 by reference numerals similar to those of plate 36.

It should be perceived that the two sinuous path structures are separated by a large central expansion chamber 96 which is divided by a concave-convex baffle plate 98. The bafile plate 98 is perforated as at 100 and its marginal edges are flanged as at 102 so that the bafile plate may be aflixed thereby to the inner wall of the casing 12 in some suitable manner, as by welding. Narrow passages 104 and 106 may be left between the edges of the baffie plate 98 and the casing 12 through which small proportions of the gases may pass.

In operation the exhaust gases enter the muffler through inlet pipe 26 and immediately are permitted to expand transversely within an expansion chamber 108 positioned between the end wall 14 and the ends of the convoluted plates 36, 38. Partial silencing is thereby effected. The predominate proportion of the gases, as they continue their passage through the muffier, have their direction of flow reversed by the imperforate baffle wall 40 until they are once more reversed and enter the sinuous path 40 along with that proportion of the gases which initially entered the path. These gases flow in a relatively thin wide path between the staggered baffle walls afforded by the convoluted plates 36, 38 and around the curved ends of the bafile. This sinuous course of travel tends to break up and reduce the regularity of the impulses; the

phenomenon being accentuated by the fact that one side P of the path 34 is defined by bafile walls which have been left imperforate.

The other side of the path as defined by baflle walls 54, 56, 58, 60 together with curved segments 62, 64 is perforated to permit a portion of the gases to flow through the openings 68 into and out of the pockets or chambers 72; thus contributing to the cushioning and silencing of the exhaust gases.

As the gases leave the tortuous path 34 and the chambers 72 through the perforations 68, they once more are permitted to expand in the central chamber 96 before the direction of fiow of at least a portion of them are reversed by the baffle 98. Next the gases pass through the bafile openings 100 into the other portion of the expansion chamber, and then once more enter the sinuous path 88 where the same phenomenon is repeated as took place in the inlet portion of the muffler. Finally the exhaust gases, silenced and reduced in speed, are discharged through the pipe 28.

Attention is now directed to the passages 82, 84 which connect the chambers under the imperforate battles with the path of noises and gases in the chambers 96. As so connected these closed chambers act as resonators which contribute a further silencing action.

From the above description it will readily be apparent that I have provided an improved sinuous type muffler in which the beneficial effects of the sinuous path of travel is materially increased by providing two separate such paths in sequence. The phenomenon is further accentuated and made more effective by insuring the passage of a greater proportion of the gases through the sinuous paths. This is accomplished by confining the necessary escape openings or perforations to but one side of the sinuous path. The efficiency and effectiveness of the muffler has further been materially increased by providing additional expansion chambers and a centrally located bafiie plate separating the two sinuous path structures. Finally to further mufiie or silence the exhaust noises, resonator chambers are introduced. It should further be apparent that each of these phenomena are permitted to occur in such a manner that they may exert their full effect Without interference or limitation.

It is believed that my invention, its mode of construction and assembly, and many of its advantages should be readily understood from the foregoing without further description, and it should also be manifest that while a preferred embodiment of the invention has been shown and described for illustrative purposes, the structural details are nevertheless capable of wide variation within the purview of my invention as defined in the appended claims.

What I claim and desire to secure by Letters Patent of the United States:

1. In a muffler comprising a cylindrical casing having intake and outlet ends at least partially closed by end walls, a plurality of pairs of convoluted plates mounted within said casing, said plates bent and arranged in complementary relationship to define a plurality of sinuous paths, at least one of the plates of each of said pairs of plates affording a transverse battle wall spaced one from the other to define a central expansion chamber, a perforated bafile plate positioned transversely within said expansion chamber, said battle plate arcuately shaped in concave-convex formation with a plurality of narrow passages positioned between the outer edges of the baffle plate and said cylindrical casing, and resonator chambers provided between at least one of said convoluted piates and the casing.

2. A mufiier comprising a casing through which the exhaust gases pass, bafiles connected to the opposite sides of said casing and arranged to form a plurality of sinuous paths for the travel of the gases through said casing, each baffle comprising spaced walls having the inner ends thereof connected whereby to form chambers, the walls of the battles connected to longitudinally alternate por- 6 tions of the sides of the casing being perforated for References Citedinthe file of this patent assage of the gases into and through the chambers ad- UNITED STATES PATENTS acent said baffles, and others of said walls comprising imperforate bafiie walls, said imperforate baffie Walls 992839 Wone et a1 May 1911 defining resonator chambers positioned adjacent the 5 1,866,004 Beamer July 1932 sinuous paths, said resonator chambers adapted to assist Egg in further mufilin the ex losive noises of said exhaust I e gases, g P 2,317,246 Bergmann June 10, 1941 2,392,247 Katcher Jan. 1, 1946 10 2,416,452 Marx Feb. 25, 1947 FOREIGN PATENTS 646,735 Germany June 19, 1937 

